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Microbiology > Chapter 5 (Notes) > Flashcards

Chapter 5 (Notes) Flashcards

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Biology 101 flashcards
1
Q

heat shock proteins are upregulated during

A

high T/stress

eg. chaperonins

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2
Q

chaperonins

A

help proteins fold correctly

eg. GroEL/GroES in E. coli

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3
Q

thermosomes

A

hollow balls that proteins fold inside of

cytosol of euk and archaea

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4
Q

protein adaptations

A

more charged aa –> salt bridges and H-bonding

hydrophobic interiors

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5
Q

lipid adapatations in psychro/thermophiles

A

psychophiles: more unsat. FA
thermophiles: more sat FA

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6
Q

membrane adaptations of thermophiles

A

fewer sterols

ether bonds

isoprenes instead of FA; harder to break

monolayer - diglycerol tetraether

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7
Q

big 2 nucleic acid adaptations in thermophiles

A

special solute 2,3-DPG - changes intracellular ion [ ] (potassium salt of this is a thermostabilizer)

heat-stable DNA binding proteins increase melting temp of DNA

histone like proteins that form nucleosome-like structures to stabilize DNA

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8
Q

other 2 nucleic acid adaptations in thermophiles

A

tight coiling in pos direction (opposite of normal) by reverse DNA gyrase

more CG bonding b/c triple bond vs. AT double bond

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9
Q

upper temperature of life?

A

strain 121 - Geogemma barossii in a black smoker hydrothermal (300 degrees C) vent called Finn in Pacific Ocean

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10
Q

strain 121 growth

A

grows in an autoclave at 121 degrees C g=25 hrs

biostatic at 130 degrees C

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11
Q

strain 121 facts

A

1 micrometer coccoid with lophotrichous flagellation

reduces Fe(III) ferric to Fe(II) ferrous to form magnetite

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12
Q

barophilic and piezophilic adaptations

A

more unsat FA to make less likely to gel at high P

pressure-active proteins expressed at high P (porin OmpH)

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13
Q

psychrophilic adaptations (need flexibility in cold)

A

fewer charged aa

more alpha-helices

cold-adapted proteins (CAPs) –> interact with DNA to serve as a cryoprotectant

sugars “betaine”, glycerol

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14
Q

water activity (aw)

A

a measure of how much water is available for use

ratio of a solution’s vapor pressure to that of pure water

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15
Q

pure water has an aw of _

A

1

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16
Q

osmolarity

A

inversely related to aw

meaure of the number of solute molecules in soln

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17
Q

aquaporin

A

membrane-cahnnel proteins that allow water to cross the cell memb. faster than diffusion

protect cell from osmotic stress

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18
Q

bacteria need aw levels greater than…

A

> .91

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19
Q

fungi tolerage aw levels of greater than…

A

> .86

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20
Q

osmoprotectants - compatible solutes

A

osmophiles and halophiles achieve osmotic balance with the envir. by producing balancing intracellular concentrations of these

non-toxic low MW organics that counter osmotic pressure from high salt or sugar outside cell

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21
Q

examples of osmoprotectants

A

sugars, glycerol, glutamate, DMSP

KCl

Trehalose

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22
Q

Trehalose

A

disaccharide osmoprotectant with high water retention capability

protects membranes from drying

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23
Q

xerophile adaptations (dessication - super dry)

A

spore formation

extracellular polysaccharides

non-reducing sugars (Trehalose) form “glass/gel” around proteins

endolithic microbes switch metabolic activity on/off

24
Q

Na circulation in alkaliphiles

A

sodium motive force in addition to proton motive force

Na+/H+ antiporters to bring protons into the cell

25
Q

oxygen is a benefit to ______

A

aerobes - organisms that use it as a TEA to extract energy from nutrients

26
Q

oxygen is toxic to…

A

cells that don’t have the enzymes to destroy ROS

eg. anaerobes

27
Q

ROS

A

reactive oxygen species

O2+ e- –> superoxide

28
Q

enzymes that can deal with ROS

A

superoxide dismutase turns it into hydrogen peroxide

catalase and peroxidase turn hydrogen peroxide into water

29
Q

______ concentrations control growth and microbial diversity

A

nutrient

humans often alter microbial ecosystems (aquatic in particular)

30
Q

eutrophication

A

sudden infusion of a large amount of a limiting nutrient

leads to bloom of microbes that threatens competing species

31
Q

how have humans caused nutrient pollution 3 ways

A

phosphate-containing soaps

nitrogen-containing runoff from farms, lawns, and golf courses

untreated sewage

32
Q

2 types of O2 usage anaeroes

A

obligate

aerotolerant

33
Q

3 types of O2 usage aerobes

A

obligate

facultative: adjust/switch to anaerobic growth
microaerophile: require O2 in small amounts

34
Q

steam autoclave

A

high T high P

PV = nRT

121 degrees C = 250 degrees F

15psi

20 min

35
Q

filtration

A

pore sizes of .2mm remove microbial cells but not viruses from soln

samples of 1ml to liters drawn through a membrane filter via vacuum or syringe

36
Q

air filtration

A

laminar flow biological safety cabinets

HEPA filters remove 99.9% of airborne material .3 micrometers or larger

37
Q

phenol coefficient test

A

compares effectiveness of disinfectants to kill microbes in 10 min

higher coefficient = higher efficacy

38
Q

disinfectant

A

kills microbes on inanimate objects

39
Q

antiseptic

A

remove pathogens from living tissue

40
Q

antimicrobial agent

A

anything that kills or inhibits growth

physical, chemical, or biological

41
Q

bacteriocidal

A

kill bacteria

42
Q

bacteriostatic

A

inhibits growth of bacteria

43
Q

sterilize

A

kills all organisms

44
Q

sanitize

A

reduce # of microbes

45
Q

chemical agents

A

bleach - Na hypochlorite soln denatures macromolecules

HClO - chlorite

46
Q

commercial disinfectants

A

damage proteins, lipids, DNA

phenolics, alcohols, aldehydes, gases

47
Q

bacteria can develop resistance to disinfectants 3 ways

A

alter FA synthesis protein that is normally targeted by triclosan

produce membrane-spanning multidrug efflux pumps

form multispecies biofilms - collaborative protection

48
Q

antibiotics

A

chemical compounds synthesized by a microbe that kills or inhibits growth of other species

eg. penicillin mimics part of the cell wall to prevent formation - bacteriocidal

49
Q

3 targets of antibiotics

A

protein synthesis

DNA replication

cell membranes

50
Q

biocontrol

A

the use of one microbe to control the growth of another

51
Q

probiotics

A

biocontrol - contain microbes that when eaten, restore balance to intestinal flora

52
Q

phage therapy

A

biocontrol - treat infectious disease with a virus targeted to the pathogen

eg. Finalyze hide wash kills E. coli on cattle

53
Q

virus size range

A

.02 - .3 micrometers (20-300nm)

54
Q

virus genome

A

RNA or DNA

ss or ds

linear or circular

55
Q

virion

A

virus particle

have a capsid protein coat

some have membranous envelope, tails/fibers, identifying surface proteins

56
Q

viruses are ___-specific

A

host

57
Q

viral replication general features (4)

A

attachment and penetration

synthesis of viral genome and proteins

assembly and packaging

release of virions

Microbiology (19 decks)

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